C++ Forcing Method Override In Concrete Class

Question

Is there a way in C++ to write a concrete class which when another class is derived from it, has a method which must be overriden. An abstract class allows the forcing of the de

Answer 1

One option is to put all the implementation of the class into an abstract superclass, and inherit from that instead.

• Move all the implementation of your concrete class T into an abstract class S.
• In S, make the must-be-overridden method a pure virtual function -- and provide a definition of it.
• T subclasses S.
• In T, override the must-be-overridden function, and call the S implementation.
• Instead of subclassing T, subclass S.
• Prevent subclassing of T.